Science 1206: Weather Dynamics Vocabulary

Vocabulary flashcards based on lecture notes for Weather Dynamics, covering heat transfer, atmospheric systems, and extreme weather events.

Weather

The physical conditions of the atmosphere at a specific time and place, including temperature, precipitation, atmospheric pressure, humidity, wind speed/direction, and sky cover.

Temperature

Qualitatively, the coolness or warmth of something; quantitatively, the average kinetic energy of the particles of a substance.

Precipitation

Any liquid or solid form of water that falls to Earth from the atmosphere, including rain, snow, and hail.

Atmospheric Pressure

The force of the atmosphere on the surface below it.

Humidity

The amount of water vapour in the air.

Sky Cover

The portion of the sky that is covered by clouds.

Earth's energy budget

The balance between the energy Earth receives from the Sun and the energy Earth radiates back into outer space after distribution through Earth's spheres.

Albedo

The reflectivity of a surface; for example, snow is very reflective while dirt is dark and absorbent.

Specific heat capacity

The heat energy needed to raise the temperature of a mass of substance by a degree, measured in $J/g^\text{o}C$.

Heat Sink

A substance that can absorb and store energy; water is a good example due to its high heat capacity, while soil and rock are poor examples.

Greenhouse effect

The trapping of the sun's warmth in the gases of a planet's atmosphere, specifically $H_2O$, $CO_2$, and $CH_4$.

Radiation

The transfer of thermal energy from energetic or unstable atoms or molecules as electromagnetic waves or particles.

Conduction

The transfer of thermal energy between objects in direct contact.

Convection

Thermal energy transfer by the movement of heated material from one place to another, specifically in fluids such as gases and liquids.

Evaporation

The phase change where liquid water becomes water vapour; this process requires an input of energy to break molecular bonds.

Condensation

The phase change where water vapour becomes liquid water; this process releases thermal energy as molecules slow down and form bonds.

Latent Heat

A measure of the attraction between particles; it is the energy absorbed or released by a substance during a state change without changing its temperature.

Latent Heat of Fusion

The amount of energy that must be absorbed by a substance in order to melt, where bonds are broken between particles.

Latent Heat of Vaporization

The amount of energy that must be absorbed by a substance in order to evaporate.

Advection

The horizontal movement of heat from one place to another in the atmosphere or oceans.

Air Mass

A very large mass of air with approximately the same temperature, pressure, and humidity throughout.

High pressure system

Created when cooling air becomes denser and draws in surrounding air from above; usually associated with clear skies and no precipitation.

Low pressure system

Created in warm areas as rising air draws in air from below; as the air rises and cools, it produces clouds and precipitation.

Coriolis effect

The change in the direction of moving air, water, or objects on Earth's surface due to the planet's rotation, directing winds to the right in the northern hemisphere.

Trade winds

Global wind systems located between the equator and $30^\text{o}$ north or south latitude.

Prevailing westerlies

Global wind systems located between $30^\text{o}$ and $60^\text{o}$ north or south latitude that typically travel from west to east.

Polar easterlies

Global wind systems located between $60^\text{o}$ and the Poles that blow from east to west away from the Poles.

Jet Streams

Narrow bands of fast-moving air (up to $300\text{ km/h}$) in the upper atmosphere created by large temperature differences and the Coriolis effect.

Front

A boundary formed between two interacting air masses of different temperatures.

Occluded front

A complex weather situation where a warm air mass is sandwiched between two colder air masses and forced upward.

Stationary front

A boundary between air masses that does not move, often because there is little difference in pressure or temperature between the fronts.

Oceanographer

A scientist who studies ocean currents.

Thermohaline circulation

Also known as the ocean conveyor belt, it is the constant motion of large ocean currents driven by changes in temperature and salinity.

Thunderstorm

Weather event occurring when water vapour in rising warm air condenses, releasing thermal energy and forming large anvil-shaped clouds.

Tornado

A rotating funnel cloud that touches the ground, formed when high-altitude horizontal winds meet large thunderstorms.

Hurricane

A rotating low-pressure system produced by very warm tropical waters where condensation releases energy that moves the air further into the atmosphere.

Nor'easters

Powerful storms with north-east winds caused by the interaction of a cold dry Arctic air mass and a warm humid air mass from the Gulf of Mexico.

El Niño

A climate pattern involving warmer Pacific waters that leads to warmer winter weather and fewer hurricanes.

Blizzard

A violent winter storm with freezing temperatures, winds exceeding $56\text{ km/h}$, and visibility reduced to less than $0.5\text{ km}$ for at least $3$ hours.